1. Technical Field
The present disclosure relates to coating solutions for magnesium alloy, and more particularly, relates to a method of prepare a coating solution thereof.
2. Description of Related Art
Magnesium alloys, made up of magnesium and other metals such as aluminum and zinc, have become, in recent years, increasingly in demand in uses as structural materials for electronic products and vehicles. Since magnesium alloy can react easily with other chemical substances such as acids, before a workpiece is used, a protective film is generally layered on an outer surface to protect the workpiece. A good corrosion resistance and low surface resistance of the protective film are required.
A typical vanadate solution used for conversion coating/treating to a surface of a magnesium alloy workpiece contains compounds containing V4+ (such as VO2+) providing vanadium, and organic acid. The vanadate solution is capable of forming a protective film on an outer surface of the magnesium alloy workpiece. Metavanadate can also provide vanadium in the vanadate solution, and is less expensive. However, protective film formed by a vanadate solution containing metavanadate is very thin, thereby possibly having difficulty meeting the quality standards of corrosion resistance and surface resistance.
Therefore, there is room for improvement within the art.